HIGH BLOOD PRESSURE

Don't blow a gasket; adjust your life

The effect of stress reduction on blood pressure isn't clear. Some studies have found that lowering blood pressure may be as simple as slow, regular breathing (aided by a device that played musical tones to guide breath rate in one report). On the flip side, a 2008 review concluded there was little reliable evidence that relaxation strategies reduced blood pressure, and a 2007 report concluded the same about meditation. (Another, in 2008, concluded that transcendental meditation may be an exception. Perhaps significantly, this meditation calls for slow, controlled breathing.)

One way to keep a lid on your blood pressure may be to adopt a pet. A 2000 study of 48 stockbrokers taking medicine for high blood pressure gave some of them pets as well. After six months, blood pressure rose for all subjects in a high-stress situation, but for those with pets it crept from 120 to 126, compared with a jump from 120 to 148 for the others.

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Exercise

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Dozens of studies have reported a link between exercise and lowered blood pressure: Some have found reductions of up to 10 mm Hg (systolic) and 6 to 10 mm Hg (diastolic) blood pressure units in people who already have hypertension.

In general, reductions are not as great for people with blood pressure in the normal range: A Belgian review of scores of studies found that for people with high blood pressure, average reductions from exercise were 6.9 mm Hg systolic and 4.9 mm Hg diastolic, and for participants who did not have high blood pressure, only 1.9 mm Hg and 1.6 mm Hg.

Age seems to matter. In one study, exercise did not reduce systolic blood pressure in older people -- ages 55 to 75 -- although it did reduce diastolic pressure. (Both readings are important.)

A possible reason: Systolic blood pressure increases as arteries grow stiffer, which happens as people age, and exercise did not reduce artery stiffness in the study participants.

Most studies about the effects of exercise have looked at aerobic exercise, although resistance training may also be effective. Recommendations call for exercising every day (or at least most days) for 30 to 45 minutes. Moderate exercise may be as effective, and possibly more so, than higher-intensity exercise.

Blood pressure can drop in just a few weeks of regular exercise. It can also pop right back up if you stop exercising.

During the exercise itself, it's normal for blood pressure to rise. But some people who have normal or only slightly raised blood pressure can experience abnormal spikes during exercise that may be a sign of high blood pressure to come. Such spikes are more likely to occur in those whose blood vessels are too stiff to expand to accommodate the increased blood flow that accompanies exercise -- a sign of early artery disease.

Just why exercise lowers blood pressure isn't clear, but there are several possibilities. Exercise makes the heart stronger, so it doesn't have to pump as hard, which in turn lowers the force on your arteries. Exercise reduces blood insulin levels, and high blood insulin has been linked to hypertension.

You should consult your doctor before beginning an exercise program, especially if you already have high blood pressure.

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Sleep

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It's wise to pay attention to your blood pressure -- but don't lose sleep over it. That may make matters worse. A five-year study published last year found that among nearly 600 adults (average age 40 at the start of the study) the fewer hours of sleep people got, the higher their blood pressure was likely to be and the more likely it was that their blood pressure would increase over time. For every hour less sleep participants got, their chances of developing high blood pressure over the study period zoomed up by 37%.

Another study of more than 10,000 adults ages 35 to 55 found that women who averaged six hours of sleep a night were 42% more likely to develop high blood pressure than women who averaged seven hours -- though it found no such effect for men. A 2006 study reported a similar finding for both genders: Of those who slept five hours a night or less, 24% developed high blood pressure during eight to 10 years of follow-up, versus 12% of those who slept seven or eight hours.

The reasons for this effect of sleep aren't clear, although it is known that blood pressure typically drops during sleep and thus brings down the average blood pressure for the day.

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Potassium, fish oil, fiber

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Results haven't been unanimous, but a good deal of research suggests that healthy doses of potassium can help lower your blood pressure.